Magnetic sound-record.



No. 831,779. PATENTEvbhSEPT.v2'5,1-9'O6.'

- V.H.IEMERSON.

MAGNETIC SOUND RECORD. AIPLIOATION FILED JAN.14.1904. RENEWED H AR, 2, 1906.

earns a'rnn 'r rroo VICTOR H. EMERSON, OF NEWARK, NEW JERSEY, ASSIGNOR TO AMERICAN GRAPHOPHONE COMPANY, OF WASHINGTON, DISTRICT OF COLUMBIA, A CORPORATION OF WEST VIRGINIA.

MAGNETIC SOUND-RECORD- Specification of Letters Patent.

' Patentedsep't. 25, 1906.

[ all whom, it may concern.-

Be it known that I, Vrcron H. EMERSON, of Newark, county of Essex, State of New Jersey, have invented a new and useful Improvement in Magnetic Sound-Records,

which is fully set forth in the following specification.

My invention consists of the production of a magnetic sound-record and in the several details hereinafter set forth.

It will best be understood by reference to the accompanying drawings forming part of this specification and in which for convenience I illustrate the invention as applied to IS a disk form of machine and tablet.

In the drawings, Figure 1 represents a side view of a talking-machine, illustrating my invention. Fig. 2 is a plan view of a soundrecord produced in accordance with my invention. g

A represents any ordinary talking-machine motor, and B is the turn-table carried thereby in operative relation to a recording device or sound-box. Upon this table 3 instead of v the recording-tablets heretofore employed I make use of a disk or tablet of non-magnetic material Osuch as glass, brass, cop er, or preferably emery paper or cloth. arried' y the sound-box D in place of the recordingneedle now employed is a needle E, that presses upon the surface of the non-magnetic disk C and is vibrated by the dia hragm in the usual manner while the dis rotates. This needle E is magnetic or magnetized and 3 5 is ofsuch consistency that it will act upon the surface of the disk C in a manner analogous to that of chalk, c'runiblin off in almost invisible particles and leaving behind on the disk C a thin line of its-own magnetic mateo rial. This needle is preferably composed of fine-powdered steel ressed and held together to form a needle in t e same manner as in the case of carbon in the well-known carbon penoils of electric-arc lamps. The result of this operation is to obtain a sound-record consisting of a non-magnetic tablet having a sinuous spiral line imparted to it, which line is both magnetic and corresponds in its irregularities with the original sound waves. For the purpose of reproduction, this magnetic sound-record is placed upon a similar talking-machine, except that in lace of the recording-needle just employed l substitute a fine pointed needle of iron or steel, which is connected to the diaphragm, but does not actually touch the magnetic line on the record, but is in very close proximity. Asthe turntable revolves and the record is carried beneath the reproducing-needle the magnetism of the line F draws the needle to and fro, producing vibrations which are imparted to the diaphragm, which vibrations, among other merits, are free from the scratching scraping sounds heretofore apparently inseparable from disk records.

I have thus described one particular embodiment of my invention, but subject to.

modifications to be made in the same without departing from the spirit of my invention. claim 1. A sound-record consisting of a tablet of non magnetic material having deposited thereon an irregular magnetic line corresponding to sound-waves.

2. The art of producin magnetic soundrecords which consists in e ositin upon the surface of a non-magnetic ta let a t 'n line or tracing produced thereon by the crumbling action 0 a ma etic needle while'the latter is being actuate waves.

In testimony whereof I have signed this specification in the presence of-two subscrib mg witnesses. I

VICTOR H. EMERSON. Witnesses? O. A. L. Maseru, Rnprn LANE Soon.-

in accordance with sound- 

